Dental matrix retainer



C. S. IVORY Filed Dec. 6, 1944 DENTAL MATRIX RETAINER 7 54 IlllillHlllIllllllIl mmmm r 46 CHESTEB INVENTOR.

5- JVoEY ii mwal ATTozA/gx I Patented May 1, 1945 u y m --'2,374,'750' i If MA X Chester S. 'Ivor y', Bala-Cynwyd; Pa.; assignor to I The-Estateofllw. Ivory, --Philadelphia, Pa.

Appheatio'n Deneinber 6,1944, seiamasfiew Z'Claims. (c1. 324a;

invention relatesto a dentalli'natrixre- -ineffective position, as will be more fully later explained, thus reducing the work that has-to 'be done in the patients mouthand the. time during which the mouthof the patient must be kept wide open. I

These and other objects, are efiected by my invention as will be apparent from the following description and claims taken in connection with the accompanying drawing forming a part of this application, in which:

Fig. 1 is a side elevation of a matrix retainer embodying my invention before itis used;

Fig. 2 is a top plan view showing the retainer as it appears when in use in the mouth of a patient;

Fig. 3 is a bottom plan view of Fig. 1;

Fig. 4 is an enlarged fragmentary elevation of the left-hand end of the retainer shown in Fig. 1;

Fig. 5 is an enlarged fragmentary vertical sectional view of the left-hand end of the retainer as shown in Fig. 2, the teeth being omitted:

Fig. 6 is a section taken on line 5-6 in Fig. 1; and 1 Fig. '7 is an enlarged perspective view of a slide or carriage forming part of the construction.

Referring to the drawing, the retainer illustrated includes a. flat, elongated body portion l0 having a slot I2 in the left-hand portion thereof. The slot l2 extends to within a short distance of the left-hand end of the body, as viewed in the drawing. At itsleft-hand end, the body portion terminates in an extension l4 having a slot 16 therein disposed at a right angle to the slot l2. The length of the slot i2 determines the range of adjustment of the device, as will later be more fully explained. To the underside of the extension IG, as viewed in Fig. 2,'is secured a boxlike structure I8 having side walls 28, a bottom wall 22 and a top wall 24. The bottom wall 22 is provided with spaced narrow slots 26, and the top wall 24 is provided with a relatively wide slot 28 which coincides with the slot I6 in the extension 55- H.- in position by a'screw or. the like. 38 engaging an extension ofthe top wallf 24 and the extension of .the body has clearlyshown in Fig. 5.:

On the topside of. the body l0,-as.viewed in Fig. 2, is slidablymounted a carriage. 32-. which is shown detached in Fig. 7. ,From Fig. 7 it will be' seen that the carriage includes sidewalls 134 36 and 38 which forma Lil-shaped structure, the

on the upper surface'of' the body as viewed. in

bottom edge ofwhichy'as viewed in Figfl, rides on the'upper surface of thebody as viewedin Fig. 2. The side wall 38 is doubled-onitselfto produce sufiicient rigidity and is proyided with a pendant tongue-40 adapte'dto engage' the slot 12 so as to permit longitudin'almovementof the carriage with reference to the body-10. It-will be noted-that the-bottom edges ofthe walls34 and 36'are cutaway so as .to produce 'a wedgeshaped space'42 between theleft-hand portion of the carriage andthe body l0, a's-bestshown in Figs. 2 and-5. r

The side wall 38 is provided with a tapped opening 44 for threadedly engaging the threaded end portion 46 of an actuating shaft or rod 48. The rod 48 passes loosely through an opening 50 in the angularly deflected end 52 of the body land is provided at its other'end with a manipulating knob or knurled handle 54. The'wall 52 terminates in a forked portion 56 which extends parallel to the wall 52 and engages a grooved nut 58. The nut 58 threadedly engages a threaded portion 60 of the rod '48 and is provided with a knurled operating wheel 62. that when the knob 54 is turned in one direction, the point 64 of the rod is moved towards and against the wall 34 of the carriage so that the .gathered ends 65 and 68 of a matrix retainer I0 may be clamped tightly between the end of the rod and the wall 34 of the carriage 32, as shownin Fig. 2. To release the ends of the matrix, the knob 54 is turned in the opposite direction; Likewise', if the nut 58 is turned in one direction, the rod 48 and the carriage 32 carried thereby are moved towards the left-hand end of the device.

and vice versa.

Operation When it is desired to use the device, the carriage 32 is moved to its extreme left-hand position,v until the tongue 40 reaches the end of the slot 12 and the slot 28 registers with the slot I6.

The yb'oxlikeq structure. isgsecured It will be seen outwith a pair of forceps. 1 turning the nut 58 until the carriage 32 is reslots 28 and I6 until they extend up at least to the level of the rod 48, as shown in Fig. 2. The knob 54 is then turned until the rod 48 tightly clamps the ends of the matrix against the wall 34 of the carriage 32. As-will be seen from Fig. 5, the body of the matrix, which is made of thin, flexible sheet metal having the desired width and tensile strength, now forms a loop considerably larger than a tooth having a cavity .C to be treated. After the cavity has been prepared, the loop of the matrix is slipped over the tooth, and the nut 58 is turned to move the carriage 32 away from the tooth, or to the right as viewed in the drawing. The movement of the carriage to the right draws the loop 10 of the matrix tightly around the tooth so that a portion of the, matrix forms a wall for the cavity C to confine the filling alloy packed into the cavity. In this position, the end portions of the matrix band are disposed in the space 42 between the bottom of the carr'iage and the body I0. When the cavity has been filled, it is merely necessary to turn the knob 54 to release the grip of the rod 48 on the ends of the matrix band, and since the endp'ortions of the matrix are in thespace 42, they are not tightly wedged between the bottom of the car- ;riage and the body I0 and the retainer can be I disengaged from the matrix by merely pulling the retainer out of the mouth.' This leaves the matrix band in the mouth and it can be pulled By this construction,

turned:to a position registering with the tooth, beforethe matrix band can be pulled vertically (downwardly or upwardly) from the tooth, is eliminated. This considerably shortens the timeduring which the mouth has to be kept openand permits removal of the matrix band at conventhere being a threaded opening in said last-mentioned side wall, a shaft having a threaded por- What I claim is:

1. A dental matrix retainer comprising an elongated body portion having an elongated slot near one end thereof, a U shaped carriage member including opposed side walls and an intermediate wall disposed on one side of said body member with said side walls extending transversely of said body member, a tongue depending from the side wall of the carriage remote from said end of said body member for slidably securing said'carriage member to said body member,

tion engaging said opening, whereby when said I ,shaft is, rotated, in one direction, the end of said shaft is moved towards the other sidewall of said carriage member, to clamp the ends of a 'matrix'band against said other side wall, and

whereby'when said shaft is rotated in the opposite direction, the end of said shaft is moved away from said side wall to release the ends of shown in Fig. 2, so as to be ready for further use. 40

said band, the underside of the portion of said carriage member facing said end of said body member being spaced from the adjacent surface of said body member, and means engaging said shaftfor moving said carriage .member longitudinally'of said body member. I

2.-The structure recited in claim *1 together with a boxlike structure secured to the opposite sidewall of said body member near said end thereof, said boxlike member having a slotin the wall thereof contiguous with said body member, and having spaced slots in the opposite wall thereof, there being a second slot in said body member near said 'end' thereof registering with said slots in the walls of said boxlike structure, said second slot and the slots in thewalls of said boxlike structure extending transversely of "said'body member and of said elongated slot.

[CHESTER s. IVORY, 

